What is .APK File?
Android Package (APK) is the package file format used by the Android operating system for distribution and installation of mobile apps and middleware. APK files are a type of archive file, specifically in zip format-type packages, based on the JAR file format, with .apk as the filename extension.
What is .XAPK File?
XAPK is a standard zip format which contains Android App Bundles, or installation package (.apk), OBB, cache asserts and other data files to make sure the app download to an Android and run successfully. Google Play Store has a limitation on the app file size, therefore for the app over 100MB, developers can use XAPK file format to allow users download the APK file on Android without corruption. There are two types of .XAPK files right now as below shows.
1. Google Play hosts the expansion files for your app and serves them to the device at no cost to you. The expansion files can be any format you choose (ZIP, PDF, MP4, etc.) and they usually contain additional resources required by your app.
To make it simple, XAPK = APK + OBB data + Cache + App Icon and Miscellaneous Info.
2. The other XAPK file format is made of Android App Bundle to generate and serve optimized APKs for each user’s device configuration. Each APK is a complete and independent version of the app, but they share the same application and package name, and be signed with the same release key. This new upload format of XAPK file allows users to get smaller, more optimized downloads because they download only the code and resources they need to run the app.